Due to the vagueness of the information need and the
uncertain representation of the content of the stored objects,
standard database techniques are not appropriate. Instead, the
concepts have to be extended to deal with vagueness and
uncertainty. As the major focus is on content-oriented search,
special techniques for representing the content of text and
multimedia objects are required.

This lecture introduces the underyling concepts of IR and
illustrates them based on special application areas.